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Corvair EMPI Camber Compensator
Posted by: The Californian ()
Date: September 27, 2019 05:41PM

Howdy!

Read this article about '60-63 Corvairs and it is convincing about if you have one

of those to do something about the handling.

I know we sure are going to!

[www.curbsideclassic.com]

Part about Camber Compensator is about half way down in article.

Article seems even handed and fair.Has constructive advice.

NOTE: Camber Compensator is not going to work as well with worn out coil

springs and shocks.

THE CALIFORNIAN



Edited 2 time(s). Last edit at 09/28/2019 07:55PM by MattNall.

Re: Corvarir EMPI Camber Compensator
Posted by: 67 airvair ()
Date: September 28, 2019 08:55AM

Seems to me that someone tested the Camber Compensator and found it did nothing (or at least very little) to the handling.

Tests on film that GM used in court was of the axle during a skidpad test. Seems the outboard axle assembly actually compresses during cornering maneuvers. Thus no need for such apparatus as a camber compensator was needed.

-Mark

Re: Corvarir EMPI Camber Compensator
Posted by: The Californian ()
Date: September 28, 2019 09:06AM

Thanks Mark

Here is proof that it works!smiling smiley

See in the picture the little car with one is beating the car without one!

Thank you for the driving tips about an early '60-63 Corvair!

Attachments:
Re: Corvarir EMPI Camber Compensator
Posted by: flat_six ()
Date: September 28, 2019 09:08AM

The early Corvair rear suspension did ok in corners on perfectly smooth surfaces. Where the risk comes in is when the car goes over a bump or dip and the car bounces. The rear suspension has what is called a roll center, which for the EM is relatively high. When the car bounces, the outboard wheel can travel through the roll center and forces acting on the bottom of the wheel can cause it to tuck under the car, even allowing the rim to dig in to the pavement under worst case conditions.

So, the camber compensator (the 64 transverse leaf spring is a variant of this) applies an upward force on that outboard wheel to minimize the propensity of that wheel to tuck under. In other words, the more the inboard wheel drops, the higher the “lifting” force that is applied to the outboard wheel.

Yes, in everyday driving it probably does little to improve handling. But in theory it does add safety margin under extreme conditions.

Re: Corvarir EMPI Camber Compensator
Posted by: caroseiii ()
Date: September 28, 2019 09:19AM

That article uses a dramatic photo of an accident which was not caused by the Corvair wagon's camber. The way the camber problem manifests is with the outside wheel tucking under. The Kovacs accident did not have a tuck under origin; the station wagon did not turn over, the driver lost control and struck a pole. So why is that photo in the article? To frighten or astonish the reader of the bad things that can happen in Corvairs. The conclusion - must need a compensator!

The Empi product seems similar to the 64 leafspring suspension but the Empi camber compensator is not the same thing. So do not conflate the design differences into the same thing. The leaf spring and redesigned softer coil springs let the vehicle understeer to reduce the Corvair's tendency to oversteer. The camber compensator does not achieve the same result. An Empi equipped vehicle will still oversteer but the outside wheel may not tuck under.

Plus, the GM testing was undertaken in mid-1962 so it wasn't in 1961 that they "knew" about the source of the problem. Unsafe has republished the videos on YouTube. [www.youtube.com]


Crawford Rose

Re: Corvarir EMPI Camber Compensator
Posted by: rnch ()
Date: September 28, 2019 09:25AM

Under normal driving conditions, with adequate tires, springs and shock absorbers AND correct tire air pressure (MOST important!), no problems with handling should be apparent.

I never noticed any.

The EM Corvair, used in the NHTSA test that exonerated the EM Corviar, did not have a camber compensator installed.

Re: Corvarir EMPI Camber Compensator
Posted by: joelsplace ()
Date: September 28, 2019 09:28AM

Lots of wrong information. Tires rolling off the rim? Fatally flawed design? Front anti-roll bar didn't do much?
Camber compensators make a big difference and even more so with worn out springs. 64 rear springs are softer than 60-63 to give the leaf a greater influence. The rear leaf reduces roll stiffness and an anti-sway bar increases it. Directly related to over or under steer.

Joel
Northlake, TX
5 Ultravans, Lost count at 100 Corvairs...




Edited 1 time(s). Last edit at 09/28/2019 09:32AM by joelsplace.

Re: Corvarir EMPI Camber Compensator
Posted by: The Californian ()
Date: September 28, 2019 09:48AM

Is this early model '60-63?

THE CALIFORNIAN

Attachments:
Re: Corvarir EMPI Camber Compensator
Posted by: joelsplace ()
Date: September 28, 2019 09:51AM

No that is 65-69

Joel
Northlake, TX
5 Ultravans, Lost count at 100 Corvairs...

Re: Corvarir EMPI Camber Compensator
Posted by: 67 airvair ()
Date: September 28, 2019 10:45AM

The '64 suspension design was done to change the roll center, thus making the car handle better. It was not to serve as a "camber compensator". If you don't understand the difference, then you don't understand suspension geometry, and are not trained as an automotive engineer. Thus you cannot be expected to understand the Corvair suspension operation, which is why Nader was so successful.

-Mark

Re: Corvarir EMPI Camber Compensator
Posted by: flat_six ()
Date: September 28, 2019 11:14AM

67 airvair Wrote:
-------------------------------------------------------
> The '64 suspension design was done to change the roll center, thus making the car handle better. It was not to serve as a "camber compensator". If you don't understand the difference, then you don't understand suspension geometry, and are not trained as an automotive engineer. Thus you cannot be expected to understand the Corvair suspension operation, which is why Nader was so successful.
>
> -Mark

The 64 transverse spring reduces the roll STIFFNESS, not the roll CENTER.

The EMPI camber compensator and the 64 transverse spring work differently to achieve the same goal: less propensity for the outboard wheel to tuck under.

The camber compensator pivots at the center mount, thus the inboard wheel "communicates" with the outer wheel. There is no change in roll stiffness. The 64 transverse spring is essentially fixed at the center. Therefore, in combination with softer coil springs, it accomplishes the same goal by providing lower roll stiffness in the rear end while preserving ride height.

Now, the 65-69 suspension does reduce the roll center significantly.

And Mark, I'll show you my engineering diploma if you'll show me yours!

Re: Corvarir EMPI Camber Compensator
Posted by: The Californian ()
Date: September 28, 2019 12:08PM

This says 1960.

Have Bill Fitch Corvair book with yearly changes.Will check it.

Is '61-63 basically the same?

THE CALIFORNIAN

Attachments:
Re: Corvarir EMPI Camber Compensator
Posted by: 66vairman ()
Date: September 28, 2019 12:13PM

Since when is an "advertisement" proof of anything?

The EMPI ad reads like those weight loss advertisements "Eat whatever you want and still lose weight, guaranteed!"

P.T. Barnum was correct.

Re: Corvarir EMPI Camber Compensator
Posted by: The Californian ()
Date: September 28, 2019 12:14PM

What year is this?

Thanks.

Attachments:
Re: Corvarir EMPI Camber Compensator
Posted by: MattNall ()
Date: September 28, 2019 12:14PM

60-64 is "basically the same".

MODERATOR
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Re: Corvarir EMPI Camber Compensator
Posted by: MattNall ()
Date: September 28, 2019 12:19PM

The Californian Wrote:
-------------------------------------------------------
> What year is this?
==================================

'65-9 very similar to '63-7 Corvette except they used a leaf instead of the coils.

MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

Re: Corvarir EMPI Camber Compensator
Posted by: flat_six ()
Date: September 28, 2019 12:23PM

60-63 no significant changes (except anti roll bar added to front suspension).

64 transverse leaf spring made significant improvement in handling "at the edge".

65-69 completely different fully independent suspension shown in some of the images in previous messages above. Nader's book even discussed the 65 suspension as "how to do it right".

Look, the Corvair - early or late - is a great car to drive. Any car can be driven to spin out or even roll. The early Corvair was proven by the NHTSA to handle on par with other cars in it's size class.

The suspension tricks and toys from the early 60's such as the EMPI camber compensator are fun to see and discuss. Even John Fitch had suspension upgrades for early Corvairs.

Re: Corvarir EMPI Camber Compensator
Posted by: The Californian ()
Date: September 28, 2019 12:39PM

Observations about this 'ghost' drawing.

The coil springs look vertical or near vertical.

The lower a arms trail back at about a 45 degree angle.

I will leave it at that.

Job 1 in any attempt at getting it to handle is to figure out what you are dealing

with.

THE CALIFORNIAN

Attachments:
Re: Corvarir EMPI Camber Compensator
Posted by: The Californian ()
Date: September 28, 2019 12:44PM

'60-64 is "basically the same".'

Thank you.

'60-63 no significant changes '

Thank you.

Re: Corvarir EMPI Camber Compensator
Posted by: joelsplace ()
Date: September 28, 2019 07:22PM

Mark,
I've never seen the Empi device in person and couldn't tell you what the technically correct term is for it but I do understand the '64 suspension. It is free to pivot in the middle or it wouldn't work. That thin strap would quickly fail if it had do deal with the force the leaf generates. It also can't reduce the roll stiffness unless it transfers the force to the other side. I'm assuming when you said roll center that was a typo.

Joel
Northlake, TX
5 Ultravans, Lost count at 100 Corvairs...

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